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Atherosclerotic occlusive disease of the lower extremity in patients exhibiting severe rest pain, ulceration, or tissue necrosis represents a serious threat to extremities. In the past two decades the surgical approach in the treatment of lower extremity ischemia has changed significantly due to better understanding of segmental disease and infrapopliteal disease. Also, better visualization of leg and foot arteries due to improved angiographic and surgical techniques aided by magnification have all significantly contributed to increased limb salvage. Vein, when available, is the ideal graft material both for supra and infrapopliteal reconstruction. Availability of vein as a conduit can be increased when ectopic veins such as cephalic etc., are used and also when short segments of veins are used with unconventional distal inflow sites such as SFA, distal deep femoral artery, and popliteal artery. However, when vein is unavailable, PTFE graft is a good option particularly in patients with life expectancy of less than three years. Better understanding of graft failure has lead to better graft surveillance with PVR, ABI and Duplex scanning. Timely intervention with either PTA or surgery has lead to better secondary patency of grafts. Veith et al. looked at amputation rates during the period of changing therapeutic approach and found both a decrease in primary and secondary amputation rate implying the effectiveness of an aggressive therapeutic approach. Not all aspects of lower extremity disease are understood. However, infrapopliteal disease has now been addressed and new, innovative therapeutic approaches have made significant advances in limb salvage.

Between Jan. 1, 1980, and Dec. 31, 1989, 2187 infrainguinal revascularization procedures were performed. In 130 of these cases with patent bypasses, hemodynamic deterioration was suspected, and urgent arteriography was performed. Twenty additional patients with aortofemoral, femorofemoral, or axillofemoral bypasses demonstrated hemodynamic deterioration. In 93% of failing grafts the condition was suspected because of recurrent symptoms or changes in the pulse examination. Two hundred eighty-five high-grade stenotic or occlusive lesions were identified in inflow arteries, outflow arteries, within the graft, or at proximal or distal anastomoses associated with these 150 grafts. One hundred sixty-one (57%) of these lesions were in patients with failing vein grafts; 115 (40%) were in patients with failing polytetrafluoroethylene (PTFE) grafts; and 9 (3%) were associated with failing composite vein/PTFE grafts. Stenotic lesions less than 5 cm in length were initially treated with percutaneous transluminal balloon angioplasty (PTA). Occlusive lesions, stenoses greater than 5 cm in length, and PTA failures were treated surgically. The overall 6-year cumulative secondary patency rate for failing grafts was 65%, and the limb salvage rate was 75%. The extended patency rate after the first intervention in the failing state was 56% at 5 years. The 5-year secondary patency rate for grafts initially treated with PTA (58%) was not significantly different (p = 0.25) from that for grafts treated initially with surgery (71%). Percutaneous transluminal angioplasty was effective for inflow stenoses of the iliac, femoral, and popliteal arteries and for some outflow lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

To determine whether unilateral aortofemoral (AUF) bypass is a safe and effective option for the treatment of unilateral limb-threatening ischemia in patients with aortic or bilateral iliac occlusive disease, we reviewed the results of 42 AUF bypasses performed using polytetrafluoroethylene grafts in patients operated on for limb salvage; 11 (26%) of the patients also underwent femoropopliteal or femorodistal (FP/D) bypasses. The indications for surgery were tissue necrosis or ulceration in 18 (43%) patients and rest pain in 17 (40%) patients. The 5-year primary graft patency and limb salvage rates for AUF bypass were 74% and 84%, respectively. The perioperative mortality rate was 5%. There were no significant differences in the primary graft patency or limb salvage rates in patients who underwent AUF bypass with or without FP/D bypass. Only 3 of 41 (7%) AUF bypass patients required subsequent femorofemoral bypass. We conclude that: (1) AUF bypass is a safe and effective surgical option in patients with unilateral limb-threatening ischemia and aortic or bilateral iliac occlusive disease; (2) the routine performance of an aortobifemoral or axillobifemoral bypass in patients with unilateral limb-threatening ischemia may be unnecessary; and (3) AUF bypass facilitates the combined inflow and infrainguinal operations that are frequently required for limb salvage in these patients.

Nonoperative therapy includes conservative noninterventional modalities and the endovascular interventional modalities of percutaneous transluminal angioplasty and a variety of laser systems and atherectomy devices. The role and impact of all nonoperative treatments are considered in the perspectives of the natural history of lower-extremity arteriosclerosis and its present surgical (operative) treatment. Nonoperative treatments may replace and/or facilitate surgical treatment in operative candidates. Nonoperative methods may also justify treatment in patients who cannot or should not be subjected to surgery. Facts and opinions relating to these uses of nonoperative treatments are presented, and the qualifications and credentialing of individuals who should be treating patients with lower-extremity ischemia resulting from peripheral arteriosclerosis are discussed.

In patients with aortoiliac occlusive disease interruption of critical collaterals during another nonvascular or cardiac operation may threaten limb viability. This occurred in four patients whose limb-threatening ischemia was precipitated by radical cystectomy with bilateral hypogastric artery ligation, left colon resection, or coronary artery revascularizations by means of the internal mammary artery. Important collateral pathways, the interruption of which may account for this phenomenon, are detailed, and approaches are outlined for prevention and management of acute ischemia in this setting.

In the management of limb-threatening infrainguinal arteriosclerosis, the short vein graft is a feature of distal-origin bypass procedures from the superficial femoral and popliteal arteries to more distal arteries. These procedures, which can only be performed in selected patients, have patency rates equivalent to those of comparable bypasses from the common femoral artery. Other advantages include the increased availability of the shorter vein graft segment that is required. Two newer operations that use short vein grafts are tibio-tibial bypasses and bypasses to isolated segments of infrapopliteal arteries. The authors' initial experience with these two procedures includes encouraging patency and limb salvage rates for periods up to 2 years in patients for whom there was no other therapeutic option short of amputation.

From January 1, 1974 to December 31, 1989, we treated 2829 patients with critical lower-extremity ischemia. In the last 5 years, 13% of patients had therapeutically significant stenoses or occlusions above and below the groin, while 35% had them at two or three levels below the inguinal ligament. Unobstructed arterial flow to the distal half of the thigh was present in 26% of patients, and 16% had unobstructed flow to the upper third of the leg with occlusions of all three leg arteries distal to this point and reconstitution of some patent named artery in the lower leg or foot. In the last 2 years, 99% of all patients with a threatened limb and without severe organic mental syndrome or midfoot gangrene were amenable to revascularization by percutaneous transluminal angioplasty (PTA), arterial bypass, or a combination of the two, although some distal arteries used for bypass insertion were heavily diseased or isolated segments without an intact plantar arch. Limb salvage was achieved and maintained in more than 90% of recent patient cohorts, with a mean procedural mortality rate of 3.3%. Recent strategies that contributed to these results include (1) distal origin short vein grafts from the below-knee popliteal or tibial arteries to an ankle or foot artery (291 cases); (2) combined PTA and bypass (245 cases); (3) more distal PTA of popliteal and tibial artery stenoses (233 cases); (4) use of in situ or ectopic reversed autogenous vein for infrapopliteal bypasses, even when vein diameter was 3 to 4 mm; (5) composite-sequential femoropopliteal-distal (PTFE/vein) bypasses; (6) reintervention when a procedure thrombosed (637 cases) or was threatened by a hemodynamically significant inflow, outflow, or graft lesion (failing graft, 252 cases); (7) frequent follow-up to detect threatening lesions before graft thrombosis occurred and to permit correction of lesions by PTA (58%) or simple reoperation; and (8) unusual approaches to all infrainguinal arteries to facilitate secondary operations, despite scarring and infection. Primary major amputation rates decreased from 41% to 5% and total amputation rates decreased from 49% to 14%. Aggressive policies to save threatened limbs thus are supported.

With multilevel arteriosclerosis, some patients undergoing infrainguinal bypass grafting will develop femoral/brachial pressure gradients only after the bypass is performed. We therefore evaluated arteriographically alternate inflow sites and measured the femoral/brachial pressure gradients before and after placement of 87 femorofemoral and 510 femoropopliteal/infrapopliteal bypasses. No prebypass femoral/brachial pressure gradients were present with and without intraarterial papaverine. However, femoral/branchial pressure gradients greater than or equal to 15 mm Hg were observed after the bypass placement in 16 femorofemoral patients and 43 femoropopliteal/infrapopliteal patients. Gradients averaged 28 +/- 8 (SD) (range, 15 to 50) mm Hg. The post femorofemoral bypass gradients were treated by immediate supplementary inflow extension to the aorta (three patients) or an axillary artery (three patients); by postoperative iliac percutaneous transluminal angioplasty (four patients) or by no treatment (six patients with femoral/brachial pressure gradients of 15 to 35 [23 +/- 5] mm Hg). The 43 postfemoropopliteal/infrapopliteal bypass gradients were treated by immediate supplementary inflow extension to the contralateral femoral artery (15 patients), the aorta (8 patients), or an axillary artery (3 patients); by postoperative iliac percutaneous transluminal angioplasty (5 patients) or by no treatment (12 patients with femoral/brachial pressure gradients of 15 to 30 [21 +/- 4] mm Hg). No thrombosis occurred in the 10 femorofemoral bypasses with postbypass femoral/brachial pressure gradients that were treated. One of the six femorofemoral patients with untreated gradients required a subsequent aortic extension, and one thrombosed after 2 years. Of the 12 untreated patients with femoropopliteal/infrapopliteal bypasses one graft occluded early, and two late failures occurred 12 and 18 months later.(ABSTRACT TRUNCATED AT 250 WORDS)

To determine systemic and local risk factors that contribute to limb loss despite a patent infra-inguinal bypass graft and how to prevent it, we reviewed 987 patients who underwent infra-inguinal bypasses at our institution. Seventy-five (7.6%) patent grafts failed to achieve a healed foot despite exhaustive attempts to do so and these patients underwent major amputation either above the knee (AKA) or below the knee (BKA). In 525 femoro-popliteal bypasses, there were 38 major amputations (29 BKA; 9 AKA) with a patent graft; in 462 femoro-distal bypasses, there were 37 amputations (22 BKA; 15 AKA) with a patent graft. The remaining 912 patients with limb salvage as well as all the patients with limb loss were evaluated with regard to systemic risk factors, quality of the run-off from the popliteal artery, continuity of the tibial artery into the arch as demonstrated on arteriography, the haemodynamic improvement obtained postoperatively, and the presence and extent of necrosis in the foot. The presence of diabetes, extensive pedal necrosis and advanced infection predispose to limb loss despite a patent lower extremity bypass graft. Patients who lost their limbs despite a functioning bypass to an isolated popliteal segment had significantly less pronounced haemodynamic improvement postoperatively. An early graft extension to a reconstituted tibial or peroneal artery or a direct bypass to a distal tibial or peroneal artery may reduce the incidence of limb loss in this setting. When a patent bypass to an isolated tibial or peroneal artery segment failed to relieve foot ischaemia, limb salvage was achieved by a distal extension to plantar arteries.

We reviewed 239 infrapopliteal reversed greater saphenous vein graft bypasses placed for critical ischemia over a 7-year period to determine the influence of vein diameter on graft patency and limb salvage. Grafts were assigned to four groups based on the minimum external diameter measured during operation: less than 3.0 mm, n = 18; 3.0 mm, n = 59; 3.5 mm, n = 67; and greater than or equal to 4.0 mm, n = 145. A pattern of increasing graft patency and limb salvage among the four groups was noted as the minimum external diameter increased from less than 3.0 mm to greater than or equal to 4.0 mm. When compared to the larger grafts greater than or equal to 4.0 mm, primary graft patency was significantly lower both for less than 3.0 mm grafts (0% for less than 3.0 mm vs 65% for greater than or equal to 4.0 mm at 3 years, p less than 0.001) and for long (greater than 45 cm) 3.0 mm grafts (38% for long 3.0 mm vs 75% for greater than or equal to 4.0 mm at 2 years, p less than 0.005). All 3.5 mm and short (less than 45 cm) 3.0 mm grafts had patency rates similar to greater than or equal to 4.0 mm veins. Thus long 3.0 mm and all less than 3.0 mm reversed saphenous vein grafts should be considered at high risk for failure. Veins with fibrotic, thick-walled segments identified during operation (n = 19) had patency rates significantly lower than nonfibrotic veins (n = 270; p less than 0.01), and this may play a role in the failure of some less than 3.0 mm minimum external diameter vein grafts.

Prospective cost and reimbursement data were collected from 10 centers in various parts of the United States on 566 patients undergoing lower extremity arterial reconstructions for limb salvage and nonlimb salvage indications. Information for each patient was available on indication and type of procedure, length of stay, the type of hospital insurance, and hospital costs/charges. Diagnosis related group payments from each center were used to determine net gain or loss for each patient. Patients were classified as having claudication or critical ischemia (limb salvage). Reimbursements matched costs/charges for the claudication group; overall mean loss in this group was only $915 per patient. However, all centers had important losses in the limb salvage group. Reimbursements averaged 60% of costs/charges, with a mean loss of $8158 per patient and an overall loss for all 10 centers of $3,653,918. An effort to remedy this inequity is progressing via a dialogue between representatives of the Society for Vascular Surgery, the North American Chapter of the International Society for Cardiovascular Surgery, and the federal government.

Secondary interventions play an important role in achieving the ultimate goal of limb salvage after primary infrainguinal interventions fail. By employing the described strategies and principles for secondary arterial reconstructions below the inguinal ligament, good results in terms of patency of the reoperated primary reconstruction or the secondary reconstruction can be obtained with significantly augmented limb salvage at a low cost in operative morbidity and mortality. These results mandate that vascular surgeons maintain an aggressive attitude toward the use of these secondary operations when a primary procedure fails to achieve or maintain its intended goal and a patient is faced with imminent limb loss because of distal ischemia.

In the past nine years, 1196 patients whose lower extremity was threatened because of infrainguinal arteriosclerosis have been treated at Montefiore Hospital. In the last six years, limb salvage was attempted in 679 or 90% of 755 patients. Femoropopliteal (318), small vessel (204) and axillopopliteal (29) bypasses were used along with transluminal angioplasty (128) and aggressive local operations to obtain a healed foot. Immediate (one month) limb salvage was achieved in 583 or 86% of the 679 patients in whom revascularization was possible. The 30-day mortality rate was 3%. The cumulative life table (LT) survival rate of all the patients undergoing reconstructive arterial operations was 48% at five years. The cumulative LT limb salvage rate after all reconstructive arterial operations was 66% at five years. The cumulative LT patency rate of femoropopliteal bypasses was not influenced by angiographic outflow characteristics of the popliteal artery but was increased 15% by appropriate reoperations to 67% at five years. Cumulative LT patency and limb salvage rates of small vessel and axillopopliteal bypasses were more than 50% at two years. Of patients undergoing arterial reconstruction, 88% of those who died within five years did so without losing their limbs. Of all the patients in whom limb salvage was attempted, 68% lived more than one year with a viable, useable extremity, and 54% lived over two years with an intact limb. We believe this aggressive approach to limb salvage is justified, and can be undertaken with a low cost in mortality, knee loss and morbidity.

The association of severe peripheral arteriosclerotic occlusive disease and cancer is unusual. Review of 14 patients with both conditions treated by arterial reconstruction demonstrated excellent limb salvage without prejudice of survival or patency. Accordingly, we believe that limb salvage operations should be considered in patients with limb-threatening peripheral vascular disease and an associated cancer.

In a series of limb salvage bypass to the popliteal and infrapopliteal arteries, the superficial femoral and popliteal arteries were used preferentially to provide inflow if these vessels were no more than minimally diseased proximal to the site of bypass origin. Cumulative life-table patency rate at 6 years for popliteal bypasses was 66% for 290 cases originating from the common femoral and 81% for 60 cases originating from the superficial femoral and popliteal arteries (P greater than 0.1). Infrapopliteal bypass patency rate at 5 years was 50% for 129 cases originating from the common femoral artery and 58% for 79 cases originating more distally (P greater than 0.25). When vein grafts alone were considered, patency rates were still not influenced by the site of origin of popliteal and infrapopliteal bypasses. Only 1 of 32 failures of a bypass with a distal origin could have been caused by proximal progression of disease. Because of these findings and multiple advantages that result from using arteries distal to the common femoral for bypass inflow, preferential use of the superficial femoral and popliteal arteries for this purpose is recommended in appropriately selected patients.

Over the last 5 years, we have performed 34 axillopopliteal bypasses to salvage threatened limbs of patients in whom standard anatomic or extra-anatomic bypasses had either failed or were not feasible. The indications for these axillopopliteal bypasses, all of which were performed with 6 mm polytetrafluoroethylene grafts, were: (1) severe atherosclerotic disease of the common, superficial and deep femoral arteries which precluded use of these vessels for inflow or outflow for a standard vascular procedure (15 cases); (2) failed aortofemoral bypass with sufficient fibrosis or disease progression in the profunda femoris artery to prevent its use in a reoperation (7 cases); (3) insufficient hemodynamic improvement and failure to heal a foot lesion after an axillofemoral bypass (9 cases); and (4) sepsis in the groin from a previously infected bypass (3 cases). Graft patency was determined by objective measures. Cumulative life table graft patency rates were 77% at 1 year, 51% at 3 years, and 45% at 5 years. Although these rates are not as good as those for our axillofemoral bypasses (75% at 5 years), 22 limbs revascularized by axillopopliteal bypasses were salvaged with function for 1 year and 9 were salvaged with function for 2 years or longer in situations in which no option other than amputation was available. This justifies the continuing use of axillopopliteal bypass in an effort to salvage those limbs imminently threatened with amputation and in which no standard reconstruction is feasible because of disease or infection.

Although advanced age has often been a relative contraindication to attempts at limb salvage, we have not regarded it as an important deterrent to arterial reconstruction. Our 6-year experience with 168 consecutive patients over 80 years of age who underwent arterial reconstruction or percutaneous transluminal angioplasty represented 18% of all patients treated with limb-threatening ischemia during this period. The average age was 84 years, with 14 patients over 90 years of age. Sixty-eight patients were men (41%) and 100 were women (59%). Indications for treatment in 189 limbs were restricted to limb salvage. One hundred eighty-two operative procedures were performed consisting of 84 femoropopliteal, 72 femorotibial, 12 axillofemoral, 11 femorofemoral, two axillopopliteal and one iliofemoral bypass. Percutaneous transluminal angioplasty was performed in 12 iliac and 14 femoral or popliteal arteries as an alternative (seven) or adjunct (19) to vascular reconstruction. The 30-day procedural mortality rate was 6%. The cumulative life table survival rate of all patients who underwent an attempt at limb salvage was 78% at 1 year, 65% at 2 years, and 54% at 3 years. Cumulative life table limb salvage rates were 84% at 1 year, 74% at 2 years, and 71% at 3 years. Overall graft patency for 182 arterial reconstructive operations was 80% at 1 year and 62% at 3 years. Of patients in whom limb salvage was attempted, 65% lived more than 1 year and 51% more than 2 years with a functional limb. Of patients who died within 5 years of treatment, 76% did so with their previously threatened limb intact. These data support an aggressive approach to arterial reconstruction in elderly patients and indicate that advanced age alone should not be considered a contraindication to attempts at limb salvage.

This study describes a technique that facilitates lower extremity "redo" revascularizations and that may increase the number of patients who can be revascularized. By using the distal deep femoral artery for bypass outflow or inflow, we were able to revascularize patients with no other accessible patent major thigh artery, to increase the use of autologous vein for infrapopliteal bypasses, and to avoid difficult groin reoperations. Thirty-seven patients (23 men) had various distal deep femoral revascularizations for limb salvage indications only (rest pain, ischemic ulcers, and/or gangrene). Techniques to expose the distal deep femoral artery directly are described and their uses discussed. We found that the type of bypass performed (e.g., axillofemoral or aortofemoral) determined the patency rate of the reconstruction. Placement of the origin or termination of the graft in the deep femoral artery did not appear to affect the results adversely.

Cost factors are an increasingly important aspect of medical care. In the United States, more than 150,000 patients per year have limb-threatening ischaemia due to infrainguinal atherosclerosis. We studied the economic impact of this disease process and its treatment in 313 consecutive patients seen at our hospital between 1979 and 1981. Minimum follow-up was 3 years. Seventy-nine percent of our patients undergoing revascularisation attempts had limb salvage with full function at 1 year and 60% had full function at 3 years. Of the patients who died, 85% died with their limbs intact. The mean patient cost for all 289 arterial reconstructions was $26,194 +/- $876 S.E. ($23,026 +/- $1117 for 166 femoropopliteal bypasses; $30,380 +/- $1349 for 123 distal bypasses). The mean length of stay (LOS) for the reconstruction group was 50 days. In this patient population, the following adverse risk factors were present: Gangrene or necrosis in the foot (72%), age more than 70 (56%), and previous vascular surgery (21%). A significantly higher cost was associated with each of these factors (gangrene, $32,653 +/- $1534; age greater than 70, $28,089 +/- $1235; previous bypass, $29,666 +/- $1962). During the same time period, initial patient costs for 24 patients undergoing primary below-knee amputation and rehabilitation were $27,225 +/- $2896 S.E. Twenty-nine percent of the patients with below-knee amputations never walked again. The nonambulatory patients had a significant continuing expenditure for institutionalisation ($100/day) or home care ($270/week). These facts document the high cost of limb-threatening arteriosclerosis and its treatment by vascular reconstruction or primary below-knee amputation.(ABSTRACT TRUNCATED AT 250 WORDS)

Graft patency is thought to correlate with resistance in the runoff bed or outflow resistance. However, accurate measurement of this parameter has been difficult. A simple and reproducible method for direct measurement of outflow resistance following completion of the distal anastomosis of a bypass graft has been developed. This method employs injection of a fixed amount of normal saline through the proximal end of the graft and measurement of the resulting integrated pressure increment by an analog computer. Division of this pressure integral by the volume injected is a measure of the outflow resistance expressed in resistance units (mm Hg/ml/min). The median outflow resistance in 31 femoropopliteal bypasses was 0.29 units with a range of 0.08-1.38 units. The median outflow resistance in 33 femorodistal bypasses was 0.7 units with a range of 0.18-2.34 units. All bypasses with an outflow resistance of 1.1 units or less remained patent for 3 months. There were 51 grafts in this group (30 femoropopliteal; 21 femorodistal) and their outflow resistance ranged from 0.08 to 1.1 units. All bypasses with an outflow resistance of 1.2 units or higher thrombosed within the first postoperative month. There were 13 grafts in this group (1 femoropopliteal; 12 femorodistal) and their outflow resistance ranged from 1.2 to 2.38 units. Eight of the 13 grafts that failed originally were subjected to thrombectomy, which was uniformly unsuccessful. Although this method does not yet allow bypass surgery to be denied to any patient, it does define a group of patients in whom thrombectomy will not be effective and should not be attempted.(ABSTRACT TRUNCATED AT 250 WORDS)

During the past 6 years, we have encountered 24 cases in which all major infrapopliteal arteries were occluded as determined by adequate preoperative angiography. Each patient initially had critical ischemia, 14 had a previous failed ipsilateral distal bypass, and seven had an unsuccessful lumbar sympathectomy. Instead of resorting to an amputation, we attempted to perform a bypass using patent branches of distal vessels. Of the 24 bypasses, 14 were to the lateral or medial plantar branches, three were to the deep plantar branch (plantar arch), three were to the lateral tarsal branch, and four were to unnamed branches of the proximal one third of the posterior tibial arteries (two) or anterior tibial arteries (two). All bypasses were performed with reversed saphenous vein with origins at or distal to the superficial femoral artery. Eight bypasses (four plantar and four unnamed branches) became thrombosed up to 30 months postoperatively, resulting in four below-knee amputations. Fifteen bypasses (all plantar branches) have been patent from 6 to 52 months (mean 26 +/- 13 months). The remaining patient required a below-knee amputation at 2 months despite a patent graft. These results underscore the value of this extended approach to limb salvage in situations previously believed to be indications for major amputations. Although bypasses to unnamed branches of the proximal tibial arteries did not fare well, those to the plantar branches and lateral tarsal branch resulted in excellent graft patency and limb salvage.

We have used a simple reproducible method to measure total outflow resistance (OR) and its proximal and distal components in 101 bypasses (46 femoropopliteal [FP] and 55 femorodistal [FD]). All bypasses with a distal OR greater than 1.2 mm Hg/ml/min failed within 3 months and all with distal OR less than 1.2 mm Hg/ml/min remained patent for at least 3 months. To evaluate the contribution of vasospasm to OR and its role in graft failure, 60 bypasses (29 FP, 31 FD) had OR measurements before and after local infusion of papaverine hydrochloride (60 mg). Within 3 months, nine grafts (all FD) occluded and 51 remained patent. All nine failures had distal OR greater than 1.2 mm Hg/ml/min before papaverine infusion. After infusion, the mean percentage decrease in both total and distal OR for all grafts was 30% and 31%, respectively. However, there was no significant difference between these papaverine-induced decreases in OR and 3-month graft failure or success. Moreover, in three bypasses, even though papaverine lowered the distal OR from greater than 1.2 to less than 1.2 mm Hg/ml/min, early occlusion occurred. In six grafts (1 FP, 5 FD) when total and distal OR before and after papaverine was greater than 1.2 mm Hg/ml/min, the graft was extended to a second distal artery as a sequential bypass. These six grafts have remained patent over 3 months. Thus measurement of OR and particularly distal OR is a most accurate predictor of early graft success or failure. Pharmacologic manipulation does not enhance the predictive value of the OR measurement. OR measurements also help to select those FD bypass cases in which extension to a second distal artery as a sequential bypass improves patency.

It has been claimed that the level of amputation is rendered higher by unsuccessful limb salvage bypass procedures. To evaluate this premise, we analyzed 242 major amputations performed for atherosclerotic vascular disease. One hundred and sixty-one amputations were performed as primary operations--50 per cent being below knee and 50 per cent, above knee amputations. Eighty-one amputations followed failure of an arterial revascularization. Twenty-three amputations, 13 below knee and ten above knee, followed late closure of such bypass procedures. Early failure of the bypass in 58 patients resulted in 46 below knee and 12 above knee amputations. After failure of 45 bypasses to arteries distal to the popliteal, 14 of the patients required above knee amputation. Following 28 unsuccessful femoropopliteal bypasses, only two patients needed above knee amputation. Thus, the risk of jeopardizing the knee joint should not be considered a major contraindication to limb salvage procedures, especially if a femoropopliteal bypass is contemplated.

In 191 instances, infrainguinal graft occlusion was presumed because of a rethreatened foot, diminished pulses and/or decreased ankle pressure. Routine urgent arteriography revealed 38 instances where the graft was patent (22 vein, 16 PTFE). Ten of these grafts were to the femoral artery, 18 to the popliteal artery and 10 were to infrapopliteal arteries. The deterioration despite a patent graft was due to development of inflow stenosis (15), vein graft lesions (13) or distal disease progression (10). All were treated successfully by percutaneous transluminal angioplasty (30) or simple local operative revisions (8). Cumulative life table patency rates 2 years after reintervention were 89% for failing reconstructions to the femoral artery, 94% for those to the popliteal artery and 89% for infrapopliteal procedures. Comparable rates for limb salvage were 90%, 100% and 100%, respectively. These findings underscore the importance of urgent angiography in suspected lower extremity graft failure. Defects may be detected before real graft occlusion occurs and appropriate interventional treatment can provide important additional periods of limb salvage.

Fourteen patients with severely ischemic extremities but relatively minor degrees of pedal gangrene or ulceration were managed without surgery. Contraindications to direct arterial reconstruction included significant intercurrent illness or generally poor surgical risk, the need for reoperative or difficult distal reconstruction, or the favorable characteristics of the actual lesion. Management consisted of bed rest, simple saline soaks, occasional gentle debridement, and antibiotics when indicated. Seven patients had complete resolution of their lesions for 3 to 48 months, and seven had improvement or stabilization for 3 to 18 months. Only three of the 14 patients have eventually required surgery with limb salvage in one. Revascularization remains the method of choice for managing most severely ischemic extremities. However, the conservative approach described represents an alternative to early amputation, attempts at revascularization, or lumbar sympathectomy in some patients with advanced ischemia. Studies of sympathectomy and pharmacologic agents as effective treatment for ischemic ulcers or gangrene should include control groups treated with the conservative measures outlined herein.

Criteria for abandoning infrainguinal arterial reconstructions in favor of major amputations should include reliable predictors not only of graft patency, but more importantly, of limb salvage. To evaluate the efficacy of intraoperative outflow resistance measurements in predicting limb salvage after infrainguinal bypasses, we have reviewed 134 such operations (64 femoropopliteal and 70 femorodistal bypasses) performed for critical ischemia. Outflow resistance measurements were divided into quartiles for femoropopliteal bypasses (Group A 0.17 mm Hg/ml/min or less, Group B 0.18 to 0.24 mm Hg/ml/min, Group C 0.25 to 0.4 mm Hg/ml/min, and Group D greater than 0.4 mm Hg/ml/min) and femorodistal bypasses (Group A 0.4 mm Hg/ml/min or less, Group B 0.4 to 0.58 mm Hg/ml/min or less, Group C 0.6 to 1 mm Hg/ml/min, and Group D 1 mm Hg/ml/min or greater). One year limb salvage rates for patients who underwent femoropopliteal bypass were 95 percent, 92 percent, 87 percent, and 67 percent from the lowest to the highest quartile (difference not statistically significant), and for those who had femorodistal bypass, they were 51 percent, 75 percent, 48 percent, and 0, respectively (p less than 0.05). Interestingly, 12 month graft patency and limb salvage rates for patients who underwent femorodistal bypass with outflow resistances between 0.59 and 1 mm Hg/ml/min did not correlate well (22 percent and 48 percent, respectively), whereas for those with outflow resistance greater than 1 mm Hg/ml/min, they were 22 percent and 22 percent, respectively. Thus, measurement of intraoperative outflow resistance is a very accurate predictor of limb salvage after infrainguinal bypass operations.

To determine whether vein graft length is a factor that influences infrapopliteal bypass patency, we reviewed 237 consecutive reversed saphenous vein bypasses performed because of critical ischemia during a 5-year period. One hundred seventeen long vein grafts (LVGs) were longer than 40 cm (42 to 92 cm, mean 60.9 +/- 9 cm) and 120 short vein grafts (SVGs) were 40 cm or shorter (6 to 40 cm, mean 24.7 +/- 8 cm). Ninety-three percent of the LVGs originated from or were proximal to the superficial femoral artery (SFA) whereas all of the SVGs originated at or distal to the SFA. The cumulative patency rate for LVGs at 3 years was 45% and for SVGs was 63% (p less than 0.025). In the absence of an intact pedal arch, 3-year patency rates for LVGs (51 cases) and SVGs (78 cases) were 22% and 53%, respectively (p less than 0.01). High intraoperative outflow resistance measurements (greater than 0.7 mm Hg/ml/min) were encountered in 25 cases. Of these, occlusion within 6 months occurred in six of seven cases with LVGs and in only 8 of 18 cases with SVGs (p less than 0.05). Wound complications at vein harvest sites occurred in 17% of LVGs and in only 6% of SVGs (p less than 0.01). Of 16 additional cases in which a proximal patch angioplasty or percutaneous transluminal angioplasty was performed tandem with a short distal vein graft, four occluded (less than 6 months) and 12 remained patent from 3 to 43 months (mean 12.6 months).(ABSTRACT TRUNCATED AT 250 WORDS)